You’re not responsible for meeting this man’s needs. You don’t need to trick him. “Please leave me alone.” If he does not do this simple thing, then you have not committed any offence and you can train yourself not to feel bad about it. You already meditate, so you might make your tendency to feel bad about this into an object of meditation.
Unfortunately, you can’t control his behavior. He might still try to sit down next to you and talk to you about things that don’t interest you. I don’t know what more you can do than ask him to stop doing this and hope he complies. “Please stop doing this. I’m just not interested. I prefer to be alone.” It is compassionate to say nothing more than this.
As for why you’re like this, that’s very likely because someone taught to you to care about other people’s feelings and didn’t teach you that their feelings are not your fault. This seems pretty common.
The stories you tell yourself about why he does this and the stories you tell yourself to explain your own behavior… they probably don’t help you much, do they?
Peace.
“Nothing like” seems to overstate things, at least to me.
Certainly, the sound in Japanese doesn’t sound aspirated the way English speakers do and expect to hear, but in listening to all the recordings at Forvo for this word, an initial “ts” seems like an entirely reasonable and fairly faithful approximation of the Japanese sound.
Granted, I would expect someone who has listened to significant amounts of Japanese to hear differences that an outsider like me wouldn’t notice, and consequently to judge differences as more pronounced than I would. Even with that in mind, “nothing like” seems like quite the exaggeration.
Moreover, and back to the original point, the pronouciation with an initial “ts” in English seems pretty obvious, just as dropping the “t” to conform to typical English phonotactics does. I wouldn’t see any reason to rule either pronunciation choice out.